David Krumholtz (born May 15, 1978) is an American actor. Krumholtz is best known for his roles as Bernard in the Santa Clause franchise (1994–present), Michael Eckman in the film 10 Things I Hate About You (1999), Goldstein in the Harold & Kumar film trilogy (2004–2011), Charlie Eppes in the CBS drama series Numb3rs (2005–2010), and Isidor Isaac Rabi in the film Oppenheimer (2023).

Krumholtz has also played other supporting roles in such well-known films as Addams Family Values (1993), The Ice Storm (1997), Beverly Hills Slums (1998), Ray (2004), Serenity (2005), Superbad (2007), Hail, Caesar! (2016), Sausage Party (2016), Wonder Wheel (2017), and The Ballad of Buster Scruggs (2018). He also played Harvey Wasserman in the HBO drama series The Deuce (2017–2019) and Monty Levin in the HBO miniseries The Plot Against America (2020).

Krumholtz made his Broadway debut in the 1992 play Conversations with My Father. He returned to Broadway playing Hermann Merz in Tom Stoppard's semi-autobiographical Holocaust play Leopoldstadt (2022), for which he was nominated for a Drama League Award.